﻿using System;
using System.Collections.Generic;
using System.IO;
using UnityEditor;
using UnityEngine;

namespace XNode
{
    /// <summary> Base class for all node graphs </summary>
    [Serializable]
    public abstract class NodeGraph : ScriptableObject
    {
#if UNITY_EDITOR
        public string NewName;

        [ContextMenu("ChangeName")]
        public void ChangeName()
        {
            if (string.IsNullOrEmpty(NewName))
                return;

            if (name == NewName)
                return;

            var oldName = name;
            name = NewName;

            var path = AssetDatabase.GetAssetPath(this);
            var absolutePath =
                $"{Application.dataPath.Replace("Assets", "")}{path}";
            var newPath =
                $"{Application.dataPath.Replace("Assets", "")}{Path.GetDirectoryName(path)}/{NewName}.asset";

            if (File.Exists(newPath))
            {
                Debug.LogError($"命名冲突，新路径已经有相应的资源 {newPath}");
                return;
            }

            File.Copy(absolutePath, newPath, false);
            File.Delete(absolutePath);

            var content = File.ReadAllText(newPath);
            content = content.Replace(oldName, name);
            File.WriteAllText(newPath, content);

            AssetDatabase.Refresh();
        }
#endif

        /// <summary> All nodes in the graph. <para/>
        /// See: <see cref="AddNode{T}"/> </summary>
        [SerializeField] public List<Node> nodes = new List<Node>();

        /// <summary> Add a node to the graph by type (convenience method - will call the System.Type version) </summary>
        public T AddNode<T>() where T : Node
        {
            return AddNode(typeof(T)) as T;
        }

        /// <summary> Add a node to the graph by type </summary>
        public virtual Node AddNode(Type type)
        {
            Node.graphHotfix = this;
            Node node = ScriptableObject.CreateInstance(type) as Node;
            node.graph = this;
            nodes.Add(node);
            return node;
        }

        /// <summary> Creates a copy of the original node in the graph </summary>
        public virtual Node CopyNode(Node original)
        {
            Node.graphHotfix = this;
            Node node = ScriptableObject.Instantiate(original);
            node.graph = this;
            node.ClearConnections();
            nodes.Add(node);
            return node;
        }

        /// <summary> Safely remove a node and all its connections </summary>
        /// <param name="node"> The node to remove </param>
        public virtual void RemoveNode(Node node)
        {
            node.ClearConnections();
            nodes.Remove(node);
            if (Application.isPlaying) Destroy(node);
        }

        /// <summary> Remove all nodes and connections from the graph </summary>
        public virtual void Clear()
        {
            if (Application.isPlaying)
            {
                for (int i = 0; i < nodes.Count; i++)
                {
                    Destroy(nodes[i]);
                }
            }

            nodes.Clear();
        }

        /// <summary> Create a new deep copy of this graph </summary>
        public virtual XNode.NodeGraph Copy()
        {
            // Instantiate a new nodegraph instance
            NodeGraph graph = Instantiate(this);
            // Instantiate all nodes inside the graph
            for (int i = 0; i < nodes.Count; i++)
            {
                if (nodes[i] == null) continue;
                Node.graphHotfix = graph;
                Node node = Instantiate(nodes[i]) as Node;
                node.graph = graph;
                graph.nodes[i] = node;
            }

            // Redirect all connections
            for (int i = 0; i < graph.nodes.Count; i++)
            {
                if (graph.nodes[i] == null) continue;
                foreach (NodePort port in graph.nodes[i].Ports)
                {
                    port.Redirect(nodes, graph.nodes);
                }
            }

            return graph;
        }

        protected virtual void OnDestroy()
        {
            // Remove all nodes prior to graph destruction
            Clear();
        }
    }
}